I saw Twiends.com before and it is not your usual way in gaining followers ... On my experience, I made followers just by following other people by:

• Typing #followback on my tweets and follow those who'll like your tweet
• Another way is to search #followback on the search bar and follow all those users that are using that hashtag.
• Follow all people that follows you.

I know what a pain it is when you can not expand your social account.
... I tried to attract followers to my Twitter account by posting regularly and made a lot of promotions. Despite all these efforts in almost 7 years on my original Twitter account I had only 250 followers...

... I use this website for almost 2 years by myself and in 4 months I managed to gain 5,000 followers for free, without any ban or block of my Twitter account. I still use this service and add a few new followers on a daily basis. The best proof that this works is my Twitter Audit with a score of 99% which is over 6 months old and was measured when I was frequently using TWIENDS.COM service.

...Maybe you're a type of person that is using bots in order to gather followers...

...It turned out that TWIENDS.COM is the best and most ethical because in other websites people after a while, massively stop to follow  (what is, of course, a total failure when you do bounty or try to build an account). In fact, all other services are fake and use bots, after some time when they get what they want, the script starts and massively stop to following your account, all previously performed treatments are for nothing then. For a year I use TWIENDS.COM only sporadically and I still have almost 4,000 followers.