Raul - great job on the girls and their hair! It may seem like a simple thing but it is a great bonding exercise and will help them feel good and you feel good. You may want to look around for what are called "hair toys" - clips and sticks etc and let the 2XD help you out with that. There are ones you can craft as well. Not sure how old your D are but one fun GAL activity might be to take them out to get their makeup done. Around here the local shops that sell makeup will often teach people how to apply their products and do the makeup that suits them best - often for free. It's what we did for D24 when she got married. They also will teach "you" how to help select product and apply it for your D - just a thought for something fun.
I'm not sure about the complex plans with the phones. On the surface it just seems like it adds confusion to the whole issue. Unlike when I was younger a lot of people just screen their calls / texts. You don't need an excuse of "there's a problem with the carrier" - just don't answer and reply when you're not busy. The main thing is to not give an excuse beyond "I was busy" and don't say "sorry" or be sorry (I broke that rule a bunch of times BTW).
The issue with your SIL and extended family is perhaps more complex. I only know a bit about Latin culture which I presume you are part of but the extended family is important for many of us even in my (Scottish/Canadian) culture. If you and your D are still part of that extended family then perhaps you should continue to be. Just don't drag them in and try to get them to take sides - that's playing with fire.
Good luck - you're doing great being your own Raul and a Dad to your D!
On BD H52, W50 T27, M26 S21, D23 BD-9-Mar-16 D-15-Jan-18 Final-19-Apr-18 I am a storyteller. The story may do you no good. But a story is never for the listener. It is always for the one who tells