hi bros, need to ask. I am on U28. I want to change to UMI 25. Is this possible?

Also, on UMI 25, I get 2GB. I am new to prepaid, let's say I put in RM25 on 1st of November.

For call charges to non umobile numbers, how to I pay for the calls? will it deduct the RM25 or do I need to add more money into the account?

Thanks LostAndFound for your reply. Appreciate it a lot. So, does this mean, in your scenario above, if I put RM30 inside, there will be RM5 for calls, but say I put RM25 inside, I won't be able to make calls at all?

Which means I must always put RM40 just incase, so that I can always make a call and not be stuck in an emergency??

Another thing, say its the same UMI25, if I put RM40 inside, and not use it up for calls, will the RM15 be brought forward to next month?

Thanks all

Anyone using UMI30? Is data 2.7GB?