Layby cancellation

I have made a lay-by for a phone at Ackermans in Pretoria. The day I made the layby I asked if I can send someone to collect or cancel the layby on my behalf and I was advised to give whoever I send my ID and the till slip. Now I sent someone to cancel the layby for me since I'm not a condition to make it to the store. I gave them my ID and the till slip as advised only to be told that I should give them my bank card as well since I made the payment with it. I then gave them my bank card the following day and still couldn't be assisted. It is said that I must make the cancellation myself. Why the runarounds? I asked about this because of my health condition before making the layby.