Travel Insurance offered via Airlink website unprofessional

I booked flights to Madagascar via the Airlink website and was offered the option of travel insurance. This is Allianz, through Next Care Health. I sent them an e-mail just to confirm that we are fully covered in Madagascar which they never responded to. I asked Airlink if they have the correct contact and the e-mail address they gave me came back. I advised Airlink and they were very unhelpful and this was the response I received "kindly note that the email address that I have provided you with is the only one that we have, the use of the Airlink website to reserve any third-party services is at the passenger’s discretion. The third-party services made available on Airlink’s website is managed by the insurance companies." Since then I managed to find a WhatsApp number and they confirmed we are not covered in Madagascar! Why then is Airlink giving this option if it does not cover you?? I asked them to then cancel the policy and they say they can only do this via e-mail but they keep denying they are receiving my e-mails even though I just respond to theirs. Now they say there must be something wrong with my e-mail, which there isn't, and hence they cannot refund me. Lovely tactic to avoid refunding clients, just deny receiving your e-mail so we can't help you. I have once again advised Airlink of what type of company they are dealing with but don't expect that they will do anything about it. Very disappointed in Airlink.