Make good vouchers not recevied after 6 weeks plus

On the 22 May I called the customer service centre to report that the dispenser of the 2 litre Liqui Fruit orange juice was inserted incorrectly and I was unable to open it up without spilling. I spoke to Misa and she apologised for the manufacturing fault, needed the manufacturing code, etc and said she would send me vouchers for the faulty product. Having not received anything in the post and not heard anything for six weeks, I called back today and spoke to Zibaya. She was unable to trace my complaint due to a new system been put in place. She asked for all my details again and assured me that I should get a response within 10 days. I need to now wait another 2 weeks, on top of the 6 weeks and hope that my mail gets delivered. Surely there is a better way to appease your customer than with complacency ?