Q: What does Islam says about serving ones parents if they are away and it is difficut to meet them?
A. You can send them gifts via mail, speak to them via telephone and make Du'aa for them. When the opportunity does arise, visit them and/or invite them to your house.
If you have hurt them in any way then you should telephone or write to ask them for forgiveness. Thereafter keep regular contact with them. By doing this you will also be making big Khidmat (service) of your parents, Inshaa Allah.
Mufti Siraj Desai