I am in russia . russia doesn't support dual sim . and my touchscreen doesn't work .I bought my Iphone 5 month ago . what should I do now ?

5 month ago I bought 1 Iphone xs Max From Iran . touchscreen doesn't work. but I am international student in moscow and now I am here . I went to service center in moscow for solve this problem . but they told me we can not support your cellphone because your Iphone is double sim cart and Russia don t support it. and told me you have to go to china :)))) is this new kinds of service !!!!! what should I do now ?