How to handle a disrespectful girlfriend

My girlfriend is someone who doesn't like to take corrections, also I notice whenever she asks for something and I said I don't have she changes. Ever since she stumbled on my bank app and saw my account balance, i noticed her demands increased. She works under federal government. But let's keep the work aside, last night her data was about to expire, she asked how to transfer it out I said she can't, it'll expire by 12 am and the data is much. I suggested her to do rollover that is buy 200 naira own, the data will carry on. She now asked me to send money for her to buy 200 own . Under normal circumstances she wouldn't ask me this. But since the day she saw my account balance. Things changed. I want to eat this, i want to buy that and I rarely tell her no. Now my issue is not even about the request. I'm the man and the provider it's how she behaves when i say i don't have. If i send money to her she's all sweet and lovely but if I say i don't have toh shikenan. Last night i told her i don't have. She stopped responding to my message immediately whereas we've been talking normal since. I called her out and check her response. I'll share the screenshot of the chat. After you've read the screenshot what do you think of everything? Personally for me, respect is very important i can't marry a woman who disrespects me. Even if your partner is wrong there's a you address it without disrespect. The date for our wedding will be set in two months from now but right now I'm thinking of calling it quits. This one is raini and see finish. What if i don't have is that, is that how she'll behave when we're married? Is that how she'll talk to me as her husband? I couldn't send the screenshot of the other chat but here's the The continuation of the conversation in text format. [7/11, 8:15 AM] her : What's interesting there ? [7/11, 8:16 AM] her : I can't sleep because you didn't buy me data or I've been living on your data or what [7/11, 8:32 AM] Me : Me I'm just correcting you. If you talk to other people that way. Continue but me i won't take such. So please check how your talk [7/11, 8:33 AM] Her: What will you do [7/11, 8:33 AM] Her: Which one is if I talk to people that way [7/11, 8:33 AM] Me: I won't do anything [7/11, 8:34 AM] Me: But i won't take such [7/11, 8:34 AM] Her: Don't insult me o [7/11, 8:34 AM]Me: So it's just me that you Raina abi [7/11, 8:34 AM] Me: Leave insult out of this [7/11, 8:34 AM] me : Your reply was very disrespectful [7/11, 8:34 AM] Her : How did i talk [7/11, 8:34 AM] Her: Yours too [7/11, 8:34 AM] Me: Okay continue [7/11, 8:35 AM] Her : You don't know how disrespectful you sound saying i didn't reply cus of data,,how much data you dey send ? [7/11, 8:35 AM] Her: You first disrespected me [7/11, 8:36 AM] Me: It's fine continue