Staking rewards not received

Hi,
Last stake reward was a month ago. 2m ago i bought 100 Dots and staked them. Choose 15 nominees and was receiving rewards daily. Then it has stopped. Then i added another 50dots as i saw that minimum stake Dots was about 115. Then it changed again to minimum 203 then i bought another 60Dots(total 213). Now the minimum is set to 250. This is ridiciolus! It just keep up going higher and we should do what? I have also tried several times to change the nominees as they became inactive( and pay fees for every change, even if remove nominee who is not active)?? Is there any way how to make sure that our stakes are receiving rewards as it is the main reason why i invested in Dots. To be able to increase my value. It is not fair that min setting keeps rising as it works only for higher investers ( which already does as they have more and therefore making more) and not for everyone equally. Also is there a way that an mobile app can be made more visible to what nominees are active or inactive for users to clearly see if their stakes are being in the right place... this now doesnt work well and it has huge room for improvement.