NA Glass & Aluminium - Bad Customer Handling

Review NA Glass & Aluminium relating to a quotation for services earlier this year. They were doing work on a cluster development in our village in Bryanston so I contacted them for a quotation. Quotation given to me by above company and accepted by myself. On accepting quotation I reminded them of the conditions of the job. It would seem on realising that they had possibly under quoted on the work they informed me that they could no longer do the work because they were too busy with big projects in Steyn City. If NA Glass & Aluminium were too busy with big contracts why did they give me a quotation in the first place.