Blu dual sim problem

[Cybortek]

Hi, I am a new subscriber and would first like to introduce myself. Please can you help, I have the Blu Win HD lte phone and it has 2 SIM cards, however if I select SIM 1 for data connection then SIM 2 gets disconnected and I can't make any calls. If I select SIM 2 then data can only be sent through SIM 2 which is a pay as you whereas SIM 1 is on contract.

Thanks