Based on what you have stated you likely do not have a case. It sounds as though the landlord or property management company took the appropriate steps once they were notified of the problem. You are free to breach the lease and leave. The offer from the apartment complex sounds as though it is actually generous as they do not have to reduce any of it.
A more important question is whether they were/are able to eradicate the bed bugs, or if they previously had notice of the bed bugs before you rented. If they are not able to remedy the bed bugs you could have a habitability claim to get you out of the lease, but only time will tell. If they knew of the bed bugs and rented to you without disclosing it to you, you may then also have a claim.
This answer provided is not comprehensive and should not be relied upon as a legal advice. Answers provided do not create nor establish an attorney-client relationship and nothing provided on this site should be considered "confidential."
The AZ Residential Landlord and Tenant Act 33-1319 addresses bedbug infestation. Landlords may not lease a unit they know is infested. If you can prove that the landlord had prior notice, yet leased the unit to you anyway, you may have a case. Otherwise, as stated by my colleague, the landlord more than fulfilled its obligations.
This reply does not constitute legal advice or the establishment of an attorney-client relationship.