Adding a DNS A record for domain name now RR's with Plusnet IP

[#1]

I've been trying to redirect our web site to another hosting company. The www record was no problem but they need the root domain directing as well i.e  an A record for hawkinsfamilylaw.co.uk pointing to 91.208.99.12
Another post on here suggested leaving the left field blank but the DNS tool wont accept that. I spoke with the helpdesk this morning and was advised that to add an A record for our domain name I should enter "hawkinsfamilylaw.co.uk."  in the left field and 91.208.99.12 in the right field. This I duly did and now if I use nslookup pointing at ns1.force9.net to query the A record for  hawkinsfamilylaw.co.uk I get three records returned in a RR list   212.159.8.91 , 91.208.99.12, 212.159.9.91. (The order changes on each request.) I now have a 1 in 3 chance of getting the right site  
Is something broken or have I configured it wrong?
Any suggestions appreciated

Mark Cresswell
Silentmonkey on behalf of Hawkins Family law.

[#2]

You need to ask support to change the 'web service' for the domain to 'semi-auto'.

[#3]

Thanks Bob  Question #75796433 raised
I'd appreciate it if this could be processed asap as I've already wasted a day on this and the site should have gone live yesterday.
Many thanks
Mark