Transfer of guarantee not done.

I purchased my laptop online and after only 2 months I had problems with my laptop. I contacted the local authorized branch of dell in Malta and they told me to transfer my guarantee. I contacted the seller and he told me that he placed the transfer, I spent around 9 months sending emails and always telling me to do steps but at the end they never gave me my guarantee. Now my guarantee expired and I am very disappointed with your service and would not recommend the product to anyone else. 

Thanks.