i cant recharge diamond in mobile legend using iphone

Recharge means, they aren't able to make purchases from "Mobile legends"

If you are receiving error "Purchase could not be completed, please contact iTunes Store Support". Then you may want to contact the iTunes Support using the below link:

https://www.apple.com/support/contact/

Assuming that 'cant recharge' means that you are trying to do an in-app purchase, what happens ? If you are getting an error message what does it say ? If you are getting a message to contact iTunes Support have you done so ?

Me also can't recharge diamond from mobile legend

What does 'can't recharge diamond' mean ?