Xperia Ray :: How To Merge Phone Number Pattern

I've a problem with phone number pattern. Normally, In my xperia ray there is three main phone number pattern:pattern 1: phone number onlattern 2: + area code phone numberPattern 3: + phone numberthe problem is, my phone do not auto recognize these pattern as one phone number. So if one contact I saved +84 12345, and I call 12345 in my country (+84 - vietnam), my phone do not display the contact.This also causes problems in merging contact from multi sources (Facebook - phone contact - mail contact etc...)