Product: Debt collection

I moved out of XXXX XXXX XXXX, located at XXXX XXXX XXXX XXXX, XXXX, OK XXXX, on XX/XX/2020. On XX/XX/2020, I received a call from a IQ Data International debt collector stating that I owed over {$500.00} dollars and that they were collecting on behalf of XXXX XXXX XXXX. XXXX XXXX never once sent me a bill, or called to inform me of any balance owed. I contacted XXXX XXXX immediately after hearing from the debt collector to try and resolve the issue. I spoke with XXXX, and then XXXX XXXX. They told me that once I move out they are not allowed to contact me anymore and the procedure is to immediately sale the debt to a collector and from that point they dont deal with the debt anymore. They also stated that the debt came from me not shampooing the carpets before I moved out, so they were going to replace the carpets. I have pictures showing the carpet in good condition. It did need to be shampooed, however it was my belief that apartments are thoroughly cleaned and carpets shampooed on behalf of the property, before the next tenant moves in. The pictures that I have show the carpet in well enough condition that simply having them cleaned should have sufficed. XXXX XXXX kept my security deposit and then charged me an additional amount over {$500.00} to replace the carpets. I am not surprised by this at all because during my time their I watched several tenants move out and XXXX XXXX  would replace the carpet in every apartment when someone moved out. A good friend of mine moved out of XXXX XXXX two months before I did and was also contacted by a collection agency within a month of moving out. Another problem that I had with this company is that my apartment had heating and air issue that caused mold in my second bedroom closet of my apartment, that I informed the office of and they never came and fixed. The heating and air system was positioned in the ceiling of my second bedroom closet. It had several issues and maintenance came out several times to try and fix it so they were fully aware of the issue but never successful in fixing it, or addressing the moisture or mold in the closet. I also have pictures of the mold in the closet. Also, XXXX XXXX office employees hold personal online and indoor garage sales in vacant apartments on the property. They inform the tenants of these sales via email. I do not know the exact amount of the collection as of right now because my call with XXXXQ Data International was disconnected and I was unable to get back in touch with them. During the first call I did not receive the name of the company and did not know who to contact. I also could not get in touch with XXXX XXXX office staff after my first inquiry about the debt. The only other attempt at communication Ive had from either company was today on XX/XX/2020. I missed a call from IQ Data International. They did not leave a voicemail, I only know it was them from calling the number back. I was unable to get in touch with a representative. I believe many of the practices of XXXX XXXX are completely unethical. I believe that they try to get over on their departing tenants, no matter how good of a tenant, or how good the condition of the apartment was left in. I moved out of the apartment because I was tasked to XXXX. Now that I am currently XXXX it is such a hassle having to deal with this, and hoping it doesnt hit my credit. I have intentions of buying a home before I return from my XXXX and this situation could greatly curtail those plans, and leave me struggling to find a place to live upon my return. Proof of phone conversations should be available through both XXXX XXXX and IQ Data International, seeing as both companies state that their calls are recorded.