Sonic Drive-In review: Drive through experience and call to the restaurant

We arrived at the 741 Rainier Ave S, Renton, Wa 98057 location at ~8:15pm on 9/9/2020. After about 2-3 minutes of waiting, we briefly heard a female Sonic employee, say "did you say you wanted, oops sorry." We could hear that she corrected her mistake as she then rolled her conversation over to the vehicle to our right, repeating the same question, to complete their order. They were then completed with their order, moved ahead, picked up their order and were gone. We were then left there for about 15 minute with no other vehicle waiting at the order drive through line or the window pickup line. Twice we said, "hello, anyone there" to the intercom, but to no avail. A new customer then pulled up to the order line to our right and was immediately helped. We started again to speak into the intercom, "HELLO! WE'RE WAITING HERE!" A female employee then came on after completing the other car's order and asked "How can I help you?" We told her we've been waiting here for 15 minute and you just help the car to our right that, just now, pulled in. She said, with an attitude, "no you haven't". We said, "no, we've been waiting here." She then said, "well what would you like to order" with even more attitude, disregarding what we've said. We than said, "What? I'd like to speak to your manager, please." She immediately said, "Well I'm the manager, what would you like to order?", with an even more disrespectful attitude. We then said, "well, we don't need to buy from you." Then she said, "OK, then, bye" and started laughing before shutting off the speaker. When we got home we called the store to ask to speak to the manager. Edgar answer and said he was the manager. We told him what had happened and he offered us something free, ignoring why we called. I asked that if he's the manager, why did she say was. He said "we have multiple managers on duty." I then asked "so, you have a manager working the drive through?" He remain silent. I asked the question again, but he did not answer. I said, "fine, then I'll just file a complaint to the corporate office, if you don't care." He then said, "I didn't say that." That was the end of the conversation.
My two cents is that it doesn't take much to speak to your costumers with respect and politeness. Had the person taking our order apologetically acknowledged their mistake and not speak to us as if we were completely unimportant and to be brushed off, this would have been a nonissue for us. However, if Sonic's position is to allow their employees to treat and speak to their customers with no value, then Sonic will not get the value of our dollars. And if Sonic has the policy to respond with, "oh well", then so will we. So, I'll just go ahead and let everyone I know, what I think Sonic is really about.