Hi again. Thank you for clarifying.
Q: Can I still have them evicted based on the fact that without my permission they brought a pet? Please explain.
A: You certainly had the right to evict the tenant when you first learned of the pet. The problem is that you have since then accepted additional rent for the pet. This could very well be seen as acceptance of the pet. Accordingly, there is a good chance that you would not be able to evict for the pet. Additionally, if there is no mention of a pet security deposit, then you have no legal basis to collect such a deposit.
Q: Will any of the following be considered harassment or illegal?
a) Tenants, have 3 phone numbers. Call each phone number everyday once until they pay.
b) call their work place.
c) report them to credit bureau on their debt
A: All of the above would be legal, though if the tenants tell you not to call their work, then you would be prohibited from doing so or it would become unlawful harassment.
Does that answer your question? Please let me know if you need clarification, as I am happy to continue helping you until you are satisfied. Also, please remember to provide a positive rating via the stars (and note that your positive rating is the only way that I'll get credit for helping you, so it is much appreciated!). Thank you. :)