Incorrect quote billed - no response from call centres

Phoned to cancel two numbers and had a very persuasive consultant convince me to keep numbers AND quoted me 2600 p month on my contract for all. Plus a whole bunch of free stuff to sweeten the deal. Invoice arrived and it's more than was quoted. PLUS none of the free stuff has been delivered yet. Phoning the call centre again and 3 times the calls were dropped on 2/27/2024. It also sounds like there is a huge party on the go but clearly a company that is all about connection would be terrible at answering phones.