Bad service / long waiting time for repairs

I bought a Doogee S58 pro from Cash Crusader's "The Glen" around 4 months ago. Shortly after buying the device, there was an issue with the phone charging so I took it back to the store for repairs. A few days after getting the phone back from repairs, I realised there was still an issue with the device not charging properly so I took it back to the store to be sent in again. It has been around 2 months of the phone being in repairs for the second time now and every time I contact the store to find out the status of repairs I am told by the person on the phone that they will contact head office and get back to me- this never happens and everytime I contact them I get the same story. I am tired of being shunted around and I am tired of the bad service. What is happening with my phone?