Returns policy absurd!

My son who has Autism purchased a TV from PC link, when picking up the tv he asked if it can be returned the guy said yes no problem. The tv was slow, volume soft, and no game mode. Netflix was delayed when connecting via the built in lan. We returned the tv 2 days later as it was over a weekend. PC link advised it would take 7 days for supplier to check tv and provide return credit and that we should check their website for another tv we would like to buy, their phone lines are down so had to rely on emails, 3 weeks later I am told there is nothing wrong with the tv and they are charging 30% handling fee for the return of the tv. I asked about exchanging for a Hisense TV instead and my request was refused. There was nothing on the invoice regarding this absurd returns policy and my son is beside himself as he bought the tv with his own money. I would understand a 10% handling fee at the most or an exchange but this is ridiculous. I also noticed that PC link does not even respond to all the complaints on hello Peter.