Trondirect UK

Bought a dual sim phone from them for £99. But after a month the phone wasn't charging. When I rang them they told me to send the charger back to them and they will send a new one, a month later still didn't get a new charger. When I rang them they said I have to pay £9.99 for a new charger. I wasn't happy but paid for it because I needed. When the charger came I pluged in the charger but the phone wasn't charging. Rang them back again they told me to send the phone back to them and they will see to it. I have send the phone back by recorded delivery. I didn't hear from them after 2 weeks. Rang them back and they said I have to pay £20 for a replacement phone. When I asked why? They said the phone was damaged. I asked him what did he mean, He said the screen was damaged. I told him the phone was send by recorded delivery, Why didn't they check the phone before taking the delivery or why didn't they ring me? He didn't want to help me all he kept saying I have to pay £20 pound for a new one. I feel so cheated by this. Don't know what to do. If any one can help please let me know what to do.