Vanguard Investments review: Their handling of clients accounts

I am having a major issue with vanguard my mom had two investments with vanguard and ira with a retairement investment account also on the benificiaries for the ira was me my now deceased son ex wife and another familly member we had just recieved the statement from vanguard stating the benifactors on the ira asking if that was still correct and it needed to be changed so we called vanguard and corrected the ira over the phone and the vanguard rep asked her what she wanted to do with the retirement investment she had she said to vanguard rep make me the beneficiary while we were on the phone he stated to have that done we would have to fill out some paperwork and return it to us she was upset saying its my money and I dont have control over it he said he was going to mail them out the next day and they came months later it was confusing to complete the first page so we contacted vanguard to make sure it was filled out correctly because ive never delt with a company as frustrating as vanguard when moms health started to decline I became the power of attorney just to ba able to ask them anything regarding moms affairs once being granted poa I never had any problems with any other financial bussiness fidelity no issues social services never had issues getting the needed 1099 for her taxes everyone else oh your poa as soon as they recieved the proof I would recieve the needed documents not vanguard they said being poa wasnt good enough so then I had to fill out a incapacitated persons form mail that in waited weeks 4 hours on the phone on hold to find out it was rejected because the last page had a date in the wrong place and they would have to email me the last two pages have them notarized and return then I can have a 1099 form to have her taxes reduced which were 18k a year and she was 88 years old but when I over nighted the two pages just notarized and corrected the date at a 28 dollar cost to be told three weeks later that it was rejected because it was done a separate time from the first pages we sent in. Then mom passed away a week from then now the taxes for the first half was never paid and with her being deceased I am no longer poa and cant write a check so thank you vanguard for not cooperating with something that shouldnt have been a issue wasnt with any of her other financial institutions Its a horror show dealing with vanguard at times ive been told I need this form to be filled out and notarized then you do it mail it to them to hear no the rep who told you that was incorrect and everything had to be redone because the customer service reps are awesome people but dont recieve enough training before they are allowed to be guiding us clueless clients. And after reading the BBB and google reviews on vanguard I now see im not the only person dealing with the same insanity the hours of hold time on the phone to be told that he or she couldnt help but the upper lever rep will be calling you back within a couple hours or days and you never get a call back its our money and they make you jump through hoops like its their money well we mailed the forms back to the address on the death benefits transfer paperwork envelope and mom passed away november 7 2021 I contacted them a couple weeks later and sent them the death certificate and now they are claiming they never recieved them and also im not the only client dealing with vanguard that has happened to with claiming they never recieved mailed in documents even ones with signature delivery so if there is anyone who can help please guide me in what can be done im getting no where with vanguard thank you and happy holidays