Unsatisfactory service

In August 2017 I went to tiger wheel & tyre in Mahikeng to do a rotation of my tyres, they were done well..on 28 October 2017 I went in to purchase two new tyres, I requested that the tyres in front be moved to the back as I had already rotated them in August 2017, . I thought a job well done ... strangely enough until I was washing my car on 14 January 2018, when I realised that both tyres from the front were not taken to the back as I had requested, one tyre is still in top form while the other is not..this is such an inconvenience to me as it requires me to buy a new tyre sooner than expected... I have been a loyal customer at the tiger wheel and tyre branch in Mahikeng...I never expected such treatment...my invoice number for that day is J ********** ....