I made Upgrade July 2021 at Vodacomshop Hatfield

I made Upgrade July 2021 at Vodacomshop Hatfield. It was a Sunday afternoon and my new cellphone was opened and I bought screen protector and cover and received watch as well and I asked consultant if watch which was sealed in box would fitt my wrist. He said yes he believe so. I left and store closed and informed consultant when I reached home that the strap of watch was too short and how will he fixed it? I was at that stage coming all the way from Rustenburg where I was working and staying. I followed up every week to find out plan of action to exchange new watch or to put on longer straps so that I can use watch. I also sent pictures of strap to short. This I followed up and up and up weekly and no joy, no solution. I last week called customer care and customer care called store and I waited 18min on line to get feedback from customer care. They said that store manager said I was supposed to bring it back within 7 days but now because I waited so long they will put longer straps on, but I have to pay for it. How fair is this to me? Why didn't the Consultant gave me this option as I requested immediately after I bought my cellphone and watch on upgrade in July? I feel store needs to replace my watch strap with longer one for free as this is not my mistake.