I've recently heard a number of sentences where でば is used at the end, seemingly to convince the listener of something. Google has failed me for the most part, aside from one article about particles in Chinese that mentions both "de" and "ba" as mid-sentence particles (I'll post a link if i can find it again), but naturally I'd rather an explanation that actually applies to Japanese.
You probably heard ってば, which is a contraction of と言えば. From 大辞林:
てば (「と言えば」の転。[...] 「ん」で終わる語に付く場合以外は、すべて「ってば」の形をとる)
The keywords here are じれったい (impatient) and 呼びかける (call out to so.). The nuance of trying to "convince the listener of something" only comes from conveying a sense of urgency with ってば.
Note that this has nothing to do with Chinese.