Bad service and waste of money

On 20/08/2020 I bought 5 Decorland aluminium blinds at Game Stellenbosch. I had the blinds trimmed for an additional cost of R375 and I paid total cost R2085. 3 of the blinds are not fitting on the windows as per my measurements given to them. I specifically requested that the blinds be trimmed according to the measurements I gave them, not to take any cm from either of them. That did not happen as these blinds are not fitting on my windows correctly and someone from outside can see inside the house on the height and length of the blinds. The trimmer took more than 5 cm on 3 of the blinds. I went to the store and asked the lady what do I need to do in order for these to be fixed, she told me that I must buy new ones and they will cut them again. As a customer I find this unacceptable as the trimmer did not follow my measurements that was written on the quotation.

I want to be reimbursed or have this resolved without involving third parties, it is not my fault that they did not take my measurements and decided to do their own thing. I'm now staying in a house with short blinds after oaying so much money for them and my safety is in danger. Please find a way to resolve this