5G and LTE Internet not working on my 2 new Sims

Hi O2 team,

I am new in Germany and moved to a new apartment (PLZ 40227). I was encouraged to take up O2 considering superior network coverage and 5G offering. I have purchased New 2 O2 Sims and Home Internet plan(1000mbits) for 2 years contract. The Home internet plan was said to take 3 weeks, therefore I was relying on the O2 sim to provide “High speed” 5G internet to work from home. 

The team was kind to offer that I will have unlimited internet for the first c.a. 25 days which should help me manage till I have fixed line internet at my home. Sounded a great plan.

To my disappointment from day 1 it has been switching `between 5G and Edge with no or poor internet connection.

My house which by the way, is on the corner of the street facing an open junction still does not get full bars from O2 (1 or 2).

I have an Official number from Vodafone and another prepaid from Lyca and they are working perfectly on 4G network inside my apartment therefore I do not see anything wrong. BUT O2 sims are not working.

I visited the O2 office in Dusseldorf Arkaden and they suggested that I should manually switch to LTE as that is stable in my area.

Even that is not working as the speeds are less than 5 mbps with regular call drops. 

I switched both the sims between 4 phones in the house and still I am not getting any connection. My other Sims are working fine on all the phones.

I also checked online for my Plz and here is the reference from your website:
Telefonie & Handy-Surfen
GSM (2G/G/E/O)
im Freien: Sehr gut
in Gebäuden: Sehr gut

Telefonie (VoLTE) & Highspeed-Internet
LTE (4G/L)
im Freien: Sehr gut
in Gebäuden: Sehr gut

Modernstes Highspeed-Internet
5G
im Freien: Sehr gut
in Gebäuden: Eingeschränkt

I called English helpline and opened a ticket which was to my utter disappointment was closed without any contact to me stating

“Hallo,

auch nach intensiver Prüfung (Nr. S26359392) konnten wir keine technische Beeinträchtigung unseres Netzes feststellen. 
Ggf. gibt es andere Gründe für die von Ihnen festgestellten Einschränkungen.

Hilfreiche Tipps finden Sie unter: https://hilfe.o2online.de/

Freundliche Grüße, Ihr o2 Team”

Further, I tested the Sims myself by walking away 60-80 meters from my house and they gave better speeds (70-90 mbps) and almost full bars, but did not work in and around the building.

I am paying extra out of my pocket to stay online when I am already paying O2 for 2 Sims, this is really not a great service or customer support, considering I am in for 2 years. I am really inclined to cancel the contract and walk over to Vodafone which I know works at my place. 

I need your support to have the team visit my apartment building not the area as it is very frustrating to work with poor internet and still pay for it. Also, internet is needed to entertainment which is not working at all.