Poor back up service

Was prescribed Allevyn wound dressing. Went to Dischem Woodmead and purchased it. The dressing is non-adhesive and the pad has two different coloured sides. I went onto the Smith and Nephew web site but there are no instructions. Called the pharmacy and was informed they did not have it and would order it. I reminded them that I had told them that I had purchased it this morning. Eventually after 8 minutes I was transferred to the shop. The phone timed out and I was cut off