My question involves a security deposit in the State of: California

I had a roommate who was not on lease.She gave me 30 day notice verbally to move out in July breaking our first agreement to move out in August.I tried to look for a roommate to move in for august but didn't find any.I ended up failing to give LL 30 day notice and got 1/3 of the security deposit back. my last roommate paid her deposit $700 to my ex roommate when she was leaving.So there was understanding that my last roommate will get her deposit back from the check I got from LL.I just felt bad for my failure to give LL 30 day notice.so at the end of August, I once texted her I will be paying her $700 (she still has the text) but one lawyer i talked to online said she cant get her deposit back without giving me proper written 30 day notice. so I emailed to her i won't pay. am I obligated to pay her deposit in this case?

The fact is:

I once texted her I will be paying her back the deposit but later I was wondering if i really have an obligation to pay her back so I talked to an online lawyer. He told me I am NOT obligated to pay her.
However i felt bad for her not getting money back, so I gave her my proposal to pay her $350 out of the goodness of my heart by emails. I sent her the half of $350 but I did not like her attitude so I told her in emails that i will not send the other half of the money.
she now thinks I can not waive to pay by my own decision and it will be a bribe to not to pay after said to pay in emails.

but I am wondering,if My promise through text message could constitute the agreement of paying her back the $700. In other words, am I obligated to pay her legally after I agreed with her moving out upon her verbal 30 day notice?
and the fact I texted her to tell her I will be paying will be the valid reason lawfully for me to pay her back?

Would it be a bribe to refuse to pay any money to her after I promised in text message and emails?