2 Months phone repair!!!!

I handed in my 2 months old CAT phone at Tyger Valley Vodashop somewhere in February 2016 for repairs, can/t even remember the date. After 5 weeks on 28/3/2016 it was ready for collection after numerous calls and grief. The back cover pin was missing. SO I sent it back again. On 1/4/2016 it was again ready for collection. Pin still missing. Sent in again. Now I get a message that the I have to pay for the pin which was in place when I gave it in the first time. The damage report does not indicate anything was missing. Now the repair centre said it was not there. I am fed up with talking to a bunch of idiots. I have had four different ref numbers. ***2 is the last one.