i havent ever seen riu send an alert to someones phone but mobile is tricky so lets make this more clarified for me to help you im going to ask a series of questions no need for fluff or filler just answer them as clear and concise as possible.
after checking around im almost 90% positive whats happening is
you have your email linked to your mobile phone, and your email is texting you.
Every Time you get an email your email texts you
so it looks like you're getting a text from rollitup but youre not youre just getting an email from rollitup but your email is texting you that you got an email.
If that is the case you need to go into your email itself and unapprove it from texting you when you get emails. That i can try to help you with but your best bet is to go to your phones support website because I am rollitup support.
If that is not the case proceed with the next 6 questions
1. did you sign up via google +, facebook ,twitter integration, or email?
2. did you enable the 2 step verification via app ?
3. what type of phone iphone or android? if android what model/make?
4. are you getting them as a Text message or IS IT a text that youve gotten an email from rollitup sometimes if you have your email associated with your phone number it will text you depending on your phone ?
5. did you buy the app from the playstore or apple store at some point? (it sometimes comes up for sale randomly)
6. are you using tapatalk?
so lets start with these, and work our way to fixing this problem
as i have stated mobiles are tricky there is a plethora of what ifs and etc.
Next time please always use support