Unhappy about service and laying

I have booked my I watches in for a battery repair in end of April. Was told I will receive the watch back repaired within two working days. After a week I still received no watch. When I did follow up they kept quiet and nothing. Almost three weeks later I received a call saying that they will start working on my watch and then I will receive the watch. Two weeks ago I received a what up that my watch cant be fixed, they will sent it back. Last week I was told it will be sent, on Monday as well then when I phoned I was told that I will be called back but no call. After that I was told two times that I will receive my watch via courier but until today no waybill for courier. I'm really angry and frustrated about the situation, and no answers. Please be very carefull before sending anything to them to be fixed. I will be opening a case at the Police for theft.