Conned by simple fix

I sent my Huawei p10 lite to a place called simple fix in farramere, my phone needed a new LCD and glass all round ,I received my phone back and my battery was ******ed! Before the phone was sent in the battery lasted a whole day and it was fast charging no problem , I get the phone back and I had to charge it twice in one day and it also didn't fast charge,, they are now saying that my battery is faulty but my phone went in with a perfectly good battery,, so I paid simple fix in farramere R1000 and I still can't use my phone because they swapped out batteries and are now expecting me to pay them for a new battery!! Simple fix are con artists!!