IP blocks blacklisted and unresponsive support

Hi,
what is your experience with OVH ip addresses being blacklisted on major RBLs and at Microsoft?

On 20th December OVH got a /24 listed at Spamhaus RBL because some spammers used some other IP addressess in this range for their activity. Unfortunately in this range my /28 was included but Spamhaus wont talk to me directly as despite having a dedicated block of IPs the abuse-mailbox provided to ripe is abuse@ovh.net

A week later - this block is still blacklisted with apparently no actions being taken by OVH. Despite filing ticket to support and writting to OVH abuse whole range is still blacklisted with no message from OVH what actions were conducted. After a brief talk on december 24 OVH provided a new range of IPs to me, but the whole range was already at Microsofts blacklist ("Blocked due to user complaints or other evidence of spamming" at Smart Network Data Service) - i.e. not really usefull to send any emails from. I did order additional Failover IP only to find out that they are blocked as-well.
To add insult to injury it seams that polish OVH branch is having a day off today as every attempt to phone call them (since they aren't answering to support cases filed through panel) ends with IVR saying "this option is currently unavailable. please file a support case instead".

Anyone is facing the same problems or have any idea what can I do to make OVH do their work and ensure every party involved that they can handle abuse complaints properly?