Good morning

i have just bought the above MIFI router but i cannot get it to recognise either of my 2 sims cards. I am in spain and am using Yoigo sim, and also i have a gifgaf sim. Both have working 4g internet with credit. The yoigo sim does nothing no internet light at all.  The gif gaff (uk) sim does show a little promise as i have both wifi and then the 3 bars to the right lit up, which didnt happen with the yoigo sim.....can any body help?