Terrible customer service

I had taken a Contract phone Huawei G7 and last year December 2017 the phone stopped working and I called them they sent a courier to come and fetch the phone since it was still under guarantee. The phone was collected on the 14 December 2017 up until today I have not received my phone back it is lying in the warehouse waiting for the courier to come and fetch it it is now almost 4 month since my phone was taken I was promised that the phone will be delivered last week and another week has started almost finishing but I have not heard anything from Green connect as to why the phone was not delivered and at this moment I am shocked at the level of their poor service I mean they don't give a damn about the fact that you don't have your phone with you whereas they had promised that the phone will be delivered but they will still be deducting the money from your account.