IX-Webhosting changing dedicated IPs without any advice in advance!

I just got called by a client of mine, that his website has been down for some time. Reason was that dedictaed IP his domains points to, has changed without any advice from IX-Webhosting. I tried immediately their support chat, that made me first wait some 15 minutes, and after that around 3 min in average for each reply. Hope the following protocal documents the situation a little better:

Thank you for contacting us via our chat line. Currently there are 2 visitors waiting, your position is 2.

You are not currently in a chat session.

Thank you for contacting us via our chat line. Currently there are 2 visitors waiting, your position is 2.

You are now chatting with 'Andrey Ivanov'

Andrey Ivanov: Welcome, my name is Andrey, please let me know how can I help you today?

Andrey Ivanov: We have not heard from you. Do you wish to continue the chat?

you: Hello, how it comes that you just change assigned IPs of my domains, xxxxx.mx was hostet at http://64.202.189.170, now once of a sudden it is at 173.83.220.168, taking down website for some while

Andrey Ivanov: Hello, please let me check.

Andrey Ivanov: Could you please provide with the domain name?

you: xxxxx.mx

you: what part of previous message, was not clear?

Andrey Ivanov: As I see all work fine from my site, but web server seems slow

Andrey Ivanov: real    0m3.006s

Andrey Ivanov: user    0m0.002s

Andrey Ivanov: sys     0m0.004s

Andrey Ivanov: Is there anything else I can assist you with?

you: yes, answer my question

Andrey Ivanov: Sorry, I just clarify the domain name.

you: My question was, how it comes you change IPs without any advise in advance?

Andrey Ivanov: Please hold on, let me check

you: To explain myself, I am not referring that website was down, but if it goes to a place nobody knows, it is pretty much the same effect

Andrey Ivanov: Could you please clarify do you change dedicated IP to shared  and back again?

you: I just got called by my client what website is down, I did not change anything, but looking it up before states clearly that dedicated IP is not the same as before, so yes, I had to change DNS pointing to the new one, in order to have less downtime possible

Andrey Ivanov: Changing IP can make you site down because DNS propagation time. But we don't change the IP.

you: You did, please revise your log-files, there has been no login from my side since then, there no doubt that domain before was available at 64.202.189.170 and no good reason, why I shoud change that IP.

Andrey Ivanov: Handling your request may take a few more minutes. Please stay online

...

you: well

Andrey Ivanov: The IP could change if you delete/add domain name on control panel or changed from dedicated IP to shared. Unfortunately I can provide you log of changing IP of your damoin.

you: Please sent me that! Also login IP from where that change was made

Andrey Ivanov: Sorry, my mistake, I can't provide with log of changing IP.

...after waiting some 30 minutes, I finally gave up to wait longer for any response.

Well I think waiting for more then one hour to get that little information, shows clearly how they work, please share my article, if you can since media is the only power to get a honost and better service in future.