I'll give you some generalized advice from what you've provided but first I need to explain some of the reasons why this is tough for anyone to answer...

First, without knowing how many customers you already have it's tough to strategize a 100% increase. If you have 1 customer, it's different than 100,000.

Second, we need to know how long it took you to acquire the customers you have. A 100% increase could be substantial and if it took you 5 years to get 50,000 clients,
it's unlikely that you'll get another 50,000 in 3 months.

Third, without knowing what you are spending on SEO, Adwords and remarketing and subsequently what you're able to spend additionally, it's difficult to advise you. For instance, if you have a $1,000/mo ad budget I might advise one thing, whereas if you have millions of dollars to spend, I might advise something else.

Fourth, and finally, for now, without knowing your current and target CPA (Cost Per Acquisition), it's difficult to advise you on what new strategies or tactics to introduce.

All that said, I'd start by running a test remarketing campaign across every social channel that allows it. This will mirror your adwords retargeting efforts by re-engaging people who are you've already had an interaction with. IT should make your SEO and PPC efforts more effective.

Next, I'd make sure you truly understand the reasons why your current clients chose you and ensure that your marketing message reflects those attributes.

After that, I'd create some awareness advertising campaigns on social media, with the client-informed marketing positioning, targeted toward a lookalike audience of your current customers. Upload an email list of current customers and create a lookalike audience. Show them videos introducing yourself and then run a remarketing campaign to video viewers.

Finally, a highly targeted direct outreach campaign on Linkedin featuring case studies of the value you bring to your existing clients is never a bad way to work on bringing in new sales.

Let me know if you'd like to discuss this further on Clarity.

Check how your service/product create value for your target customer. The best way to capture value is by creating value. Only when your customer see benefit they would buy it from you. For further inputs on customer acquisition and growth feel free to setup a call.

Your capabilities to serve depend 1) different countries' legal systems, 2) how your clients contracted, and 3) debt recovery team in the specific country.

I am being credit controller 20 years back, managing over $100 million debts across Asia. Base on my experience, if I want to engage you, you need to give me confidence that you know how to deal with the specific country legal system well and good understanding of contract law to review my contracts, and finally, do you really have a team in that specific country to recover debt for me.

Therefore, forget all SEO, AdWordsm, etc ... if I am in the position to advise, I will review your business and marketing strategy and conduct a product-market match before advise what marketing contents to be developed. From here, an approach marketing campaign with multipile waves of reaching out and follow up to generate quality leads and close more customers. (some of my clients had generated more than 500% customers in 3 months.