Unable to contact after repeated calls to supplier

An awning was supp**** and installed 18 months ago. I noticed signs of rust on the outer surface a few weeks ago and 'phoned the supplier about this. I was told I should clean it with thinners. All this achieved was to remove the coating (paint of some sort) and have now got a bare metal patch, which will probably rust quicker. Calls to him are now answered with a message that the subscriber's mail box is full, and I should try calling later! I feel the material used was not coated properly or is of a sub standard quality.<br>