TELKOM COVERAGE LTE

I have signed up with TELKOM wi-Fi for about 2½years now. When i signed up my coverage was LTE (showned to me by TELKOM) and that is what i have paid for, but now for about 2 - 3 months our coverage dropped to 3G and sometimes 4G. The DOWNLOAD speed from 34.59 to 1.87 and UPLOAD speed from 3.4 to 0.06. When i phoned TELKOM they just say that our coverage is 3G, and that is not what i have signed for. We have complained about this on the 17/4/18 and the on the 7/5/18. and still i dont have a propper answer from TELKOM. And then I am still billed form LTE. I need to know what is going on in our area - Lanseria