Thats exactly why I have bought and earned SP and I still have no real influence or any real hope of getting any under the current system.
I am not saying that the fact you cannot easily acquire influence right now is not a problem. I agree it is a problem.
There is a huge difference though between your issue though (you did not get as much influence as you had hoped/wanted/expected) and a violation of contract.
Any SP that you bought and earned is following the rules of the blockchain. You may have thought/hoped/expected that it would give you more influence than it did - but that is not a breach of contract. The blockchain is still following the same rules for you that it does for everyone else, which is that you have a stake-weighted influence in the rewards pool, based on the amount of your vested shares compared to the total.