Zero customer service

In the past I've received excellent service from Phonetradr and successfully sold two phones through them. What has changed in the past 2 years? This time around my phone has sat with them for months even though I've priced it at the recommended selling price. I can't lay this at their feet, unless it's not receiving sufficient exposure. What I am upset about is the following: 1. Customer service (or rather, lack thereof!). Telephone calls go unanswered, as do emails. 2. I received a bot message with a very cheeky offer on my phone. I had the option to (i) accept (ii) reject (iii) counter offer. I chose to counter offer only for the bot to tell me it didn't recognise my offer (typed in the exact same format as the offer). The bottom asked if I wanted to speak to an agent. He'll, yes! Well, that was days ago, with follow up messages, emails and phone calls. NOTHING! NO CONTACT WHATSOEVER.